The present invention relates to a reshapable hair styling composition.
Fixing the hairstyle is an important element in hair styling, and involves maintaining a shaping that has already been carried out, or in simultaneously shaping and fixing the hair.
In accordance with the invention, the term xe2x80x9chair styling compositionxe2x80x9d relates to any kind of hair composition that can be used to effect hair styling, for example fixing compositions, shampoos, conditioners, permanent waving compositions, hair care products, and hair treatment products.
The most prevalent hair styling compositions on the cosmetic market for shaping and/or maintaining the hairstyle are spray compositions comprising a solution, usually alcohol- or water-based, and one or more materials, generally polymer resins. One of the functions of polymer resins is to form links between the hairs, these materials also being called fixatives, in a mixture with various cosmetic adjuvants. This solution is generally packaged either in an appropriate aerosol container, which is pressurized with the aid of a propellant, or in a pump flask.
Other known hair styling compositions include styling gels and mousses, which are generally applied to the wetted hair before brushing or setting it. In contrast to the conventional aerosol lacquers, these compositions have the disadvantage that they do not allow the hair to be fixed in a shape created before their application. In fact, these compositions are essentially aqueous and their application wets the hair and is therefore unable to maintain the initial shape of the hairstyle. In order to shape and fix the hairstyle, therefore, it is necessary to carry out subsequent brushing and/or drying.
Such hair styling compositions all have the same disadvantage that they do not allow the hairstyle to be later modified to a desired shape, which is other than that formed initially, without starting the styling and fixing operations again. Moreover, under various kinds of stress, the hairstyle has a tendency to take on an undesirable permanent set, which cannot easily be modified. Also in the styling process, one desires hair conditioning benefits, such as ease of combing and soft hair feel appearance.
A subject of the invention is a reshapable hair styling composition comprising, in a cosmetic vehicle appropriate for hair, at least one polyurethane.
Another subject of the invention is a reshapable hair styling composition comprising, in a cosmetic vehicle appropriate for hair, at least one dispersion comprising at least one polyurethane.
Another subject of the invention is a reshapable hair styling composition comprising, in a cosmetic vehicle appropriate for hair, at least one dispersion comprising at least one polyurethane and a water and/or solvent medium of dispersion.
Another subject of the invention is a reshapable hair styling composition comprising, in a cosmetic vehicle appropriate for hair, at least one dispersion comprising at least one polyurethane in a water and/or solvent medium of dispersion, said at least one polyurethane being obtained by reacting:
(a) an isocyanate terminated polyurethane prepolymer being obtained by reacting: (i) at least one polyactive hydrogen compound insoluble in said medium of dispersion, wherein said polyactive hydrogen compound is selected from alkyl, aryl, and aralkyl structures optionally substituted in and/or on the structure by N, O, and/or S groups; (ii) at least one polyisocyanate, and (iii) at least one polyactive hydrogen compound soluble in the medium of the dispersion,
(b) at least one polyfunctional chain extender; and
(c) at least one chain terminator.
The medium of dispersion can be, for example, an alcohol mixture or a water/alcohol mixture.
The term xe2x80x9creshapablexe2x80x9d hair styling composition means a hair styling composition providing hair styling that can be restored or modified without new material or heat being applied. For example, in order to restore or modify the hairstyle in case of xe2x80x9cdroopingxe2x80x9d or loss of setting (dishevelment), no new materials, such as water or any form of fixing agent, or heat are required. Thus, to provide a xe2x80x9creshapablexe2x80x9d effect means to provide a hair styling that can be restored or modified without new material or heat being applied. The efficacy of the composition can be long lasting, such as 10-24 hours, giving rise to a durable styling effect. Other terms, which may be synonymous with reshapable, include repositionable, remoldable, restyleable, and remodellable.
It is a further subject of the invention to provide a method for treating hair, characterized in that the composition according to the invention is applied to the hair before, during, or after shaping the hairstyle.
As used herein, a xe2x80x9cdispersionxe2x80x9d means generally a two-phase system where one phase comprises discrete particles distributed throughout a bulk substance, the particles being the disperse or internal phase, and the bulk substance the continuous or external phase. In an embodiment of this invention, at least a portion of the polyurethane exists as the discrete particle in the continuous phase. The term xe2x80x9cdispersionxe2x80x9d does not necessarily mean that the entire polyurethane polymer needs to be insoluble; at least some of the polymer can be soluble in the medium. Dispersions may result from the use of certain components that are insoluble in the solvent system. It is desirable that the dispersion remains stable under ambient conditions. In one embodiment, the dispersions are stable at room temperature for more than 30 days, also for more than 90 days, further also for more than 180 days, and more further also for more than 360 days.
The polyurethane dispersion may be made by forming the isocyanate terminated polyurethane prepolymer, chain extending the prepolymer, and chain terminating the prepolymer to yield a polyurethane polymer that may be stable and dispersed in the water and/or solvent system. Although it is possible to carry out the foregoing steps sequentially, this is not necessary. The order of the steps may be changed and certain steps can be combined, such as chain extension and chain termination or prepolymer formation and chain termination. For example, an excess of chain extender can also serve as the chain terminator. The steps and the components are discussed in detail below.
As used herein the term xe2x80x9cisocyanate terminated polyurethane prepolymerxe2x80x9d, or alternately referred to as xe2x80x9cisocyanate functional polyurethane prepolymerxe2x80x9d means a reaction product of a mixture comprising at least one polyisocyanate, at least one medium insoluble polyactive hydrogen compound, and at least one medium soluble polyactive hydrogen compound. In general, the reaction occurs with a molar excess of isocyanate groups to produce an oligomer, which may have urethane, urea, and/or thiourethane functional groups. The prepolymer can be prepared at an equivalent ratio of isocyanate groups to active hydrogen reactive groups of greater than 1.6:1, also greater than 1.8:1, and further also about 2.0:1 or greater.
As used herein, the term xe2x80x9cpolyactive hydrogen compoundxe2x80x9d means a compound having an average functionality greater than 1, such as greater than 1.8, and further such as about 2.0 or greater but less than about 6, such as less than about 4, and further such as about 3 or less. The term is understood to include compounds that have (i) alcohol groups on primary, secondary, and tertiary carbon atoms, (ii) primary and secondary amines, (iii) mercaptans, and (iv) mixtures of these functional groups.
Accordingly, the inventive polyurethane dispersions can contain urea linkages, e.g., from the reaction of isocyanate functional polyurethanes with amines, these polymers more appropriately being labeled as xe2x80x9cpolyurethane-ureasxe2x80x9d.
The polyactive hydrogen compounds useful for preparing the prepolymer have a molecular weight of 62 to 10,000, also 200 to 5,000, and further also 400 to 3,000.
The xe2x80x9cA component,xe2x80x9d also referred to as the (a)(i) component, i.e., the medium insoluble polyactive hydrogen compound, may generally be present at concentrations of at least 5% by weight, also at least 10% by weight, and further also at least 20% by weight of the total of components (a)(i), (a)(ii), and (a)(iii). The phrase xe2x80x9cmedium insolublexe2x80x9d means generally that at least 1 gram of the compound is not soluble in about 4 grams of the medium of the dispersion at about 25xc2x0 C. Certain polyactive hydrogen compounds may require heating to melt to determine whether they are soluble or insoluble using this characterization method.
Several different types of polyols are suitable for use as the xe2x80x9cA component,xe2x80x9d generally including polyols chosen from those having alkyl, aryl, and aralkyl structures optionally substituted in and/or on the structure by N, O, and/or S groups. The compounds generally useful as the xe2x80x9cA componentxe2x80x9d may have a number average molecular weight at least above about 300, such as above about 400, and further such as above about 500. But such compounds may have a number average molecular weight at least below about 10,000, such as below about 5,000, and further such as below about 3,000.
Monomeric polyols, such as the C36 dimer fatty alcohol available as PRIPOL 2033 from Uniqema North America, Chicago, Ill., can be used. Oligomeric polyols having, on average, from about 1.6 to about 4 hydroxyl or amino groups can also be used. One embodiment of an oligomeric polyol useful as the xe2x80x9cA componentxe2x80x9d is aliphatic polyester polyol based on diacids and/or diols that have greater than 10 carbon atoms, such as greater than 20 carbon atoms. Commercial examples of polyester polyols are PRIPLAST 3191, 3192, 3196, 3197,1906, and 1907 from Uniqema North America, Chicago, Ill., believed to be based on a 36 carbon atom diacid and/or diol. Specific constituents used in preparation of these diols are believed to be for PRIPLAST 3192xe2x80x94dimer acid, adipic acid, and 1,6-hexane diol; for PRIPLAST 3193xe2x80x94dimer acid and ethylene glycol; for PRIPLAST 3194xe2x80x94dimer acid, adipic acid, and ethylene glycol; for PRIPLAST 3196xe2x80x94dimer acid and 1,6-hexane diol; for PRIPLAST 3197xe2x80x94dimer acid and dimer diol; for PRIPLAST 1906xe2x80x94isophthalic acid and dimer diol; and for PRIPLAST 1907xe2x80x94terephthalic acid and dimer diol. Another embodiment of an oligomeric polyol is hydroxy terminated polyalkadienes, including polybutadienes and polyisoprenes, such as POLY bd resin from Elf Atochem North America, Philadelphia, Pa.
An oligomeric polyol may be chosen from hydrogenated polyalkadiene polyols, including hydrogenated polyisoprene and hydrogenated polybutadiene, the latter having no less than 19 wt % 1,2-butadiene addition. Commercial examples of hydrogenated polybutadiene diols include KRATON L-2203 from Shell Chemical, Houston, Tex., and POLYTAIL resins from Mitsubishi Chemical, Tokyo, Japan.
In another embodiment, the xe2x80x9cA componentxe2x80x9d is an oligomeric polyamine. Suitable oligomeric polyamines include amine terminated butadiene polymers and butadiene-acrylonitrile copolymers. A commercial example of such an amine is HYCAR ATBN from B. F. Goodrich, Cleveland, Ohio.
Silicone polyols and perfluoroalkyl functional polyols, when used, should not be present in greater than about 5 weight percentage of the overall composition as their low surface energy properties would be expected to detract from the desired adhesion characteristics based on the teachings of U.S. Pat. No. 5,679,754 (Larson et al.), whose disclosure is incorporated herein by reference.
Representative polyisocyanates that can be used to form the isocyanate functional polyurethane include aliphatic, cycloaliphatic, and aromatic polyisocyanates. Suitable aliphatic polyisocyanates include aliphatic isocyanates and diisocyanates. Diisocyanates may, for example, be chosen from dicyclohexylmethane 4,4xe2x80x2-diisocyanate (commonly referred to as H12MDI) and 3,5,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane (commonly referred to as isophorone diisocyanate or IPDI), both available from Bayer Corp., Pittsburgh, Pa., under the trade designations DESMODUR W and DESMODUR I, respectively. In addition, diisocyanates may be chosen from (i) tetramethylene diisocyanate, (ii) 1,3-bis(isocyanatomethyl) cyclohexane, (iii) 1,3-bis(1-isocyanato-1-methylethyl)benzene, (iv) diphenylmethane 4,4xe2x80x2-diisocyanate (commonly referred to as MDI), (v) 4,4xe2x80x2,4xe2x80x3-triisocyanatotriphenyl methane, (vi) polymethylene polyphenylene polyisocyanate (commonly referred to as polymeric MDI), (vii) toluene diisocyanate (commonly referred to as TDI), (viii) hexamethylene diisocyanate (commonly referred to as HDI), (ix) dodecamethylene diisocyanate, and (x) m- and p-xylene diisocyanate.
Other useful polyisocyanates include those described in U.S. Pat. No. 3,700,643 (Smith et al.) and U.S. Pat. No. 3,600,359 (Miranda), whose disclosures are incorporated herein by reference. Mixtures of polyisocyanates can also be used, such as ISONATE 2143L, available from Dow Chemical Co., Midland, Mich.
The polyurethane prepolymer is made dispersible in the medium by using a xe2x80x9cB componentxe2x80x9d, also referred to as the (a)(iii) component, i.e., the at least one medium soluble polyactive hydrogen compound. That is, the B component may act to stabilize the polyurethane dispersion in the medium. The phrase xe2x80x9cmedium solublexe2x80x9d means generally that at least 1 gram of the compound is soluble in about 4 grams of the medium at about 25xc2x0 C. Certain compounds may require heating to melt to determine whether they are soluble or insoluble using this characterization method. The medium used in this characterization method should be the same medium used to prepare the dispersing medium. For example, alcohol-water solubility may be imparted to this compound by the presence of an ionic group, a moiety capable of forming an ionic group, or a polyester, polyether, or polycarbonate group having a ratio of 5:1 or less, such as 4:1 or less, carbon atoms for each oxygen atom, and mixtures thereof.
When present, the ionic group of the B component may be chosen from anionic, cationic, and zwitterionic groups. The cationic groups may originate from the isocyanate or polyol component but most conveniently are added in as a polyol component. The cationic group may be incorporated directly into the prepolymer. For example, a quaternary diol such as VARIQUAT 1215 may be reacted into the prepolymer directly. Alternatively, a precursor group can be reacted into the prepolymer and then be rendered cationic in a subsequent reaction. For example, active hydrogen functional tertiary amines, such as methyldiethanolamine and its polyethoxylated adducts may be incorporated into the prepolymer backbone and subsequently protonated with a mineral or organic acid to form an ionic salt or alkylated to form a quaternary ammonium group. Reaction of the incorporated tertiary amine with hydrogen peroxide, propane sultone, or lactone gives zwitterionic moieties. Stabilizing cationic components may be very water-soluble, generally having a solubility in water of at least 1% by weight, such as in excess of 10% by weight. Stabilizing cationic compounds may have the following structure:
Rxe2x80x94N+(R2)[(OCH2CH2)nOH]2Xxe2x88x92
where R is chosen from C1-C18 alkyl, C6-C18 aryl, and C6-C18 aralkyl structures optionlly substituted in and/or on the structure by N, O, and/or S groups; R2 is chosen from a hydrogen atom and C1-C18 alkyl groups; n is an integer from about 1 to about 200, such as about 1 to about 50, and further such as about 1 to about 20; and Xxe2x88x92 is chosen from halides, sulfates, methosulfates, ethosulfates, acetates, carbonates, and phosphates.
Cationic stabilizing compounds may be chosen from protonated and alkylated methyl diethanol amines as well as PEG 2 cocomonium chloride and PEG-15 cocomonium chloride available from Witco/Sherex as VARIQUAT 638 and VARIQUAT K1215 respectively.
It is possible to incorporate cationic compounds that have a single reactive hydrogen group. However, they are not considered optimal.
The anionic stabilizer used in the present invention can be present on either the isocyanate component or the polyactive hydrogen component. Typically, and most conveniently, the anionic stabilizer is present as a polyol component. The anionic group can be chosen from sulfonates, phosphonates, phosphates, and carboxylates; also from sulfonates and carboxylates; and further also from sulfonates. The sulfonates may be chosen from the sulfonated polyols described in U.S. Pat. No. 4,738,992 (Larson et al.), whose disclosure is incorporated herein by reference. The sulfonates include polyesterdiols having the following structure: 
wherein M is a cation chosen from H, alkali metals, alkaline earth metals, and primary, secondary and tertiary ammonium cations, such as ammonium, methylammonium, butylammonium, diethylammonium, triethylammonium, tetraethylammonium, and benzyltrimethylammonium cations; and each R1 is the same or different and chosen from divalent aliphatic groups having an average molecular weight of about 200 to about 600 comprising ether and/or ester functional groups chosen from:
xe2x80x94CH2xe2x80x94CH2xe2x80x94(OCH2xe2x80x94CH2xe2x80x94)nxe2x80x94,
xe2x80x94C(CH3)Hxe2x80x94CH2xe2x80x94(OC(CH3)Hxe2x80x94CH2xe2x80x94)nxe2x80x94,
xe2x80x94(CH2)4xe2x80x94(O(CH2)4)nxe2x80x94, and
xe2x80x94(CH2)mxe2x80x94COxe2x80x94[xe2x80x94Oxe2x80x94(CH2)mxe2x80x94COxe2x80x94]nxe2x80x94 groups;
where m is an integer from about 2 to about 5; and n is an integer from about 2 to about 15.
Suitable carboxylate and carboxylic acid functional polyols include dimethylolpropionic acid and its polyethoxylated derivatives as well as acid grafted polyethers such as the UCARMOD polyols available from Union Carbide Specialty Chemicals Div., Danbury, Conn. These can be neutralized with an organic or inorganic base either before or after preparation of the prepolymer.
In one embodiment, to obtain alcohol-water or water dispersibility, the ionic equivalent weight of the prepolymer (gram prepolymer per equivalent of ionic functionality) should be in the range of about 1000 g/equiv to about 15000 g/equiv, also about 1500 g/equiv to about 12500 g/equiv, further also about 2000 g/equiv to about 10000 g/equiv, and more further also about 2500 g/equiv to about 7500 g/equiv.
Examples of oligomeric polyactive hydrogen compounds that have sufficient polar non-ionic groups such as ether or ester functionality that provides a ratio of 5 or less carbon atoms for each oxygen atom to give alcohol-water solubility include (i) polyoxyalkylene diols, triols, and tetrols, (ii) polyoxyalkylene diamines and triamines, (iii) polyester diols, triols, and tetrols of organic polycarboxylic acids and polyhydric alcohols, and (iv) polylactone diols, triols, and tetrols having a molecular weight of about 106 to about 2000. Examples of oligomeric polyols and polyamines include (i) polyethylene oxide homopolymers (e.g., CARBOWAX series from Union Carbide, Danbury, Conn.), block copolymers of ethylene oxide and propylene oxide (e.g., PLURONIC surfactants from BASF Corporation, Mount Olive, N.J.), random copolymers of ethylene oxide and propylene oxide (e.g., UCON FLUIDS from Union Carbide, Danbury, Conn.), silicone copolyols, as well as surfactants based on polyethylene oxide as described in U.S. Pat. No. 4,667,661 (Scholz et al.), whose disclosure is incorporated herein by reference, (ii) polyoxypropylene diols and triols such as the ACCLAIM series of polyols from Arco Chemical, Newtown Square, Pa., (iii) polyether diamines, and triamines such as the JEFFAMINE series available from Huntsman Corporation, Salt Lake City, Utah, (iv) polyether polyols such as the TERATHANE series (which is a polyoxytetramethylene diol) available from E.I. du Pont Co., Wilmington, Del., and the POLYMEG series available from Quaker Oats Co., Chicago, Ill., (v) polyester polyols such as MULTRON, which is a poly(ethyleneadipate) polyol, available from Bayer Corporation, Pittsburgh, Pa., (vi) polycarbonate diols such as those available from Stahl USA Co., Peabody, Mass., and (vii) polycaprolactone polyols such as the TONE series available from Union Carbide, Danbury, Conn. Polythioether polyols are also useful.
In addition, when alcohol insoluble polyols are used, low molecular weight medium soluble xe2x80x9cmonomericxe2x80x9d polyols may be used. Examples of the monomeric polyols include ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, diethylene glycol, 1,1,1-trimethylolpropane, pentaerythritol, aminoethanol, and the like. When used, the amount of the monomeric polyols should be kept low to minimize the viscosity of the prepolymer.
The reaction of the components discussed above (i.e., the A component, the polyisocyanate, and the B component) to form the prepolymer will depend on the specific components chosen. Aromatic isocyanates are generally much more reactive than aliphatic isocyanates and may be reacted with polyols without the need for heat because the reaction will be exothermic. The reaction may be run as 100% solids (i.e., little to no solvent) or may be carried out in an optionally polar organic solvent unreactive with the isocyanate. Such solvents include, for example, acetone, methyl ethyl ketone (MEK), methoxypropanol acetate (PM acetate), dimethyl acetamide, tetrahydrofuran, N-methyl-pyrrolidinone, and mixtures thereof. In one embodiment, the solvent used will not require removal in the final composition. It is also possible to incorporate solvents and/or plasticizers that are left in the prepolymer that become part of the finished dispersion.
When using aliphatic isocyanates with polyfunctional alcohols, high solids concentrations and elevated reaction temperatures from about 50xc2x0 C. to about 80xc2x0 C. are desirable so that high conversions of monomers to polymer can occur in a reasonable time, e.g., less than eight hours, also less than three hours. Embodiments incorporating isophorone diisocyanate or hexamethylene diisocyanate and aliphatic primary or secondary alcohols are typically heated to about 80xc2x0 C. for about 2 hours in the presence of a small amount of catalyst.
Useful catalysts include metal salts such as dibutyltin dilaurate and dibutyltin diacetate, and amines, such as triethylamine, DBU (1,8-diazabicyclo[5.4.0] undec-7-ene), and DABCO (1,4-diazabicyclo [2.2.2]octane), in useful concentrations of from about 0.01 to about 1.0 mole percent (relative to the isocyanate reagent). In one embodiment, catalysts are non-irritating and non-sensitizing to skin. The catalysts may be chosen from those that can become bound to the polymer backbone and are thus non-leachable, such as FASTCAT 4224 from Elf Atochem and certain alcohol and amine functional tertiary amine catalysts such as methyldiethanolamine and tetramethylguanidine. In batch preparations from about 100 to about 1000 grams, one may use about 0.1 gram of FASTCAT 4224 per 100 gram of total resin.
The ratio of polyisocyanate to polyactive hydrogen compound is adjusted such that the prepolymer has a molecular weight of about 1000 to about 25000. The equivalents of polyisocyanate may exceed the total equivalents of polyactive hydrogen compound (i.e., total equivalents of active hydrogen), the equivalent excess being from about 1.1:1 to about 6:1, also from about 1.5:1 to about 3:1, and further also from about 1.8 to about 2.2.
Once the prepolymer is formed, the molecular weight should be increased to yield a composition with the desired properties. This step is accomplished by reacting the prepolymer with a xe2x80x9cchain extender.xe2x80x9d As used herein the term xe2x80x9cchain extenderxe2x80x9d means a polyactive hydrogen compound having a functionality of about 2 to about 4, also of about 2 to about 3, and further also about 2 and generally having a molecular weight of about 30 to about 2000, such as about 30 to about 1000. In one embodiment, the chain extenders are chosen from polyfunctional alcohols, amines, and carboxylic acid hydrazides. In another embodiment, the chain extenders are chosen from polyfunctional amines and carboxylic acid hydrazides.
Useful polyamines include ethylenediamine; 1,6-diaminohexane; piperazine; tris(2-aminoethyl)amine; and amine terminated polyethers such as those marketed as JEFFAMINE by the Huntsman Corporation, Salt Lake City, Utah, for example JEFFAMINE D230 and JEFFAMINE D400.
Useful carboxylic acid hydrazides include adipic acid dihydrazide and oxalic acid dihydrazides. Particularly useful polyfunctional alcohols include alkylene diols having 2 to 24 carbon atoms such as ethylene glycol; 1,4-butane diol; and 1,8-octane diol. Useful polythiols include 1,2-ethanedithiol; 1,4-butanedithiol; 2,2xe2x80x2-oxytris(ethane thiol) and di- and tri-mercaptopropionate esters of poly(oxyethylene) diols and triols. Water is also useful as a polyfunctional chain extender as it reacts with isocyanate to form an unstable carbamic acid, which loses carbon dioxide to liberate an amine. This amine is then available to react with another isocyanate.
When the prepolymer has a functionality of 2 or less and the chain extender is difunctional, the ratio of isocyanate to active hydrogen in the chain extension step is from about 0.6:1 to about 1.2:1, also from about 0.75:1 to about 1.0:1, and further also from about 0.80:1 to about 1.0:1 (except when water is used as the sole chain extender, in which case water can be present in large molar excess). When the prepolymer has a functionality higher than 2, due to the use of polyactive hydrogen compounds or polyisocyanates with a functionality greater than 2, it may perhaps be necessary to proportionately adjust downward the ratio of isocyanate to active hydrogen present in the chain extender to prevent gelation and keep the molecular weight of the polyurethane polymer formed in an appropriate region to provide reshapable hair styling performance.
In an environment with high concentrations of a lower alcohol (typically more than 20:80 w/w alcohol to water), endcapping of the isocyanate functional prepolymer may occur as the isocyanate reacts with the alcohol solvent. Therefore, use of a polyfunctional amine as the chain extender is highly suitable because amines are much more reactive toward isocyanate than the lower alcohol, giving better control of molecular weight.
In one embodiment, the dispersing medium may be chosen from lower alcohols (C1 to C4 branched or straight chain aliphatic alcohols), water, and mixtures thereof. The lower alcohols may be chosen from ethanol, n-propanol, and 2-propanol (IPA). Alternatively, the medium may be chosen from water, IPA, ethanol, and mixtures thereof. The alcohol to water ratio may range from 20:80 to 90:10 w/w and also from 70:30 to 85:15. In general, higher amounts of alcohol will result in a dispersion that exhibits faster dry times.
The solvent system may comprise other solvents. For example, other rapid evaporating, skin compatible solvents may be used, such as hexamethyldisiloxane (HMDS); cyclic silicones (D4 and D5); C4-C10 alkanes including isoparafins such as Permethyl 97A and Isopar C; acetone; hydrofluoroethers (HFEs) and the like. Certain HFEs, such as HFE 7100, have an added benefit in certain applications; when such as solvent is added to hydro-alcohol mixtures in levels above about 15 to about 25 wt %, the composition becomes non-flammable.
The reaction that forms the polyurethane polymer is stopped by the use of chain termination species (the chain terminator), used to stop the growing polymer chain thereby controlling the molecular weight and the physical properties of the polymer. In one embodiment, a diamine chain extender, used in excess, functions as a chain terminator. Another useful chain terminating agent is 2-amino-2-methyl-1-propanol (AMP), used in about 0.1 to about 2.0 parts, based on the total weight of the polyurethane polymer. Monofunctional amines or alcohols are useful as chain terminators. An example of a monofunctional alcohol is ethanol, which can further function as part of the dispersing medium.
The dispersions of the present invention may be prepared in any number of methods. In a first method, the prepolymer can be added to the solvent as 100% solids or diluted first with a different solvent that may or may not be removed later. If the solvent is to be removed, it may be more volatile than either water or the lower alcohol. In another method, the prepolymer can be dispersed in part of or in all of the solvent mixture or in a portion of the solvent mixture with subsequent addition of additional solvents. Any additional solvent added after dispersion could be added slowly in order to ensure the dispersion maintains stability. In yet another method, the prepolymer and/or dispersion solvent may be heated or cooled. In yet another method, the prepolymer may be dispersed in the solvent prior to, simultaneously with, or after the chain extender and chain terminator have been added to the solvent mixture.
One embodiment of the dispersion method involves heating the prepolymer to temperatures of about 45xc2x0 C. to about 80xc2x0 C. to reduce its viscosity. The heated prepolymer is added to a rapidly stirring high shear mixing apparatus, such as a homogenizer, containing the solvent. Thereafter, the amine, a chain extender, is added at a predetermined rate. Alternatively, for certain formulations, the amine can be added to the solvent mixture first and the heated prepolymer added to the rapidly mixing solvent mixture.
For an alcohol-water system, the level of lower alcohol may be at least 20% by weight, such as at least 40%, further such as at least 60%, and more further such as at least 70% by weight. In one embodiment, the level of lower alcohol is not more than 90%, such as not more than 85%.
The weight average molecular weight of the polyurethane in the final dispersion is generally about 5000 to about 50000, also about 15000 to about 35000, and further also about 20000 to about 30000.
In one embodiment, the method of controlling the level of reshapability may comprise adding monofunctional amines prior to or during the chain extension step. This method will result in end capping of some isocyanate groups thereby limiting the molecular weight. The monofunctional amines generally have the following structure:
R1R2NH
where R1 and R2, which are the same or different, are each chosen from a hydrogen atom and C1 to C22 alkyl, C6 to C28 aryl, and C6 to C28 aralkyl groups optionally substituted in available positions by N, O, and/or S groups, including alcohol, tertiary amine, quaternary amine, ketone, and carboxylic acid substitutions. In one embodiment, the monofunctional amines are those that would have low skin irritation if left unreacted in the formulation, such as 2-amino-2-methylpropanol or higher alkyl primary and secondary amines as well primary and secondary alkanolamines.
The formulations of the present invention may also include plasticizers that can be added either to the prepolymer directly or can be added to the solvent mixture. The use of plasticizers may allow for the use of less solvent, and therefore produce more rapidly drying films. Where plasticizers are used, the base prepolymer should be formulated to ensure the plasticized adhesive has sufficient tensile strength. This could require the use of lower molecular weight polyols (lower NCO equivalent weight prepolymers). Preferred plasticizers are cosmetically acceptable emollients such as those disclosed in U.S. Pat. No. 5,951,993 at column, 17 line 35 to column 21, line 6, whose disclosure is incorporated herein by reference.
An embodiment of the invention provides a reshapable hair styling composition comprising, in a cosmetic vehicle suitable for hair, at least one dispersion comprising at least one polyurethane, leading to a styling material following application to the fibers and drying.
It is a further subject of the invention to provide a method for treating hair, characterized in that the composition according to the invention is applied to the hair before during, or after the shaping of the hairstyle.
In another embodiment of the invention, the polyurethane has a glass transition temperature (Tg) ranging from about xe2x88x92100 to about 15xc2x0 C. According to the present invention, the Tg of the polyurethane is obtained following the application of the polyurethane dispersion to a substrate and drying. The glass transition temperature is determined by the Differential Scanning Calorimetric method (DSC).
The composition according to the invention may comprise at least one other constituent, which is conventional in cosmetics, chosen from preservatives; perfumes; UV filters; active haircare agents; plasticizers; anionic, cationic, amphoteric, nonionic, and zwitterionic surfactants; hair conditioning agents such as silicone fluids, fatty esters, fatty alcohol, long chain hydrocarbons, emollients, lubricants, and penetrants such as lanolin compounds, protein hydrolysates, and other protein derivatives; anionic, cationic, amphoteric, nonionic, and zwitterionic polymers; dyes; tints; bleaches; reducing agents; pH adjusting agents; sunscreens; preservatives; thickening agents; and perfumes.
The appropriate cosmetically acceptable vehicle is adapted to the method of application selected. The vehicle preferably comprises an appropriate solvent to which may be added additives such as gelling agents, foaming agents, and silicones.
It is understood that the person skilled in the art will know how to choose the additional constituents and their amount in the composition according to the invention, such as the constituents of the vehicle, so as not to adversely affect or substantially affect its reshapable hair styling properties.
The compositions according to the invention can be provided in any form known from the prior art, which is appropriate for their application to the hair, including in the form of a vaporizable composition, mousse, gel, or lotion.
The composition may be in any of the conventional forms including, but not limited to, shampoos, hair rinses, permanent waving compositions, waving compositions, hair dye compositions, hair straightening compositions, hair fixing products, hair styling gel products, products to use before or after a hair dye treatment, products to use before or after a permanent waving treatment, hair straightening compositions, products to use before or after a hair straightening treatment, and fixing foams.
The composition according to the invention may be vaporizable, for example by a pump, or may be a pressurized aerosol composition. It may be vaporizable by a dispensing valve controlled by a dispensing head, which in turn comprises a nozzle, which vaporizes the aerosol composition. A vaporizable composition according to the invention comprises an appropriate solvent. Advantageously, the appropriate solvent comprises at least one solvent chosen from water and lower alcohols. In accordance with the invention, the term lower alcohol means a C1-C4 aliphatic alcohol, preferably ethanol.
When the vaporizable composition according to the invention is an aerosol composition, it additionally comprises an appropriate amount of propellant. The propellant comprises compressed or liquefied gases, which are normally employed for the preparation of aerosol compositions. Suitable gasses include compressed air, carbon dioxide, nitrogen, and gases, which are soluble or otherwise in the composition, such as dimethyl ether, fluorinated or non-fluorinated hydrocarbons, and mixtures thereof.
The present invention additionally provides an aerosol device comprising a vessel comprising an aerosol composition, which comprises on the one hand a liquid phase (or juice) comprising at least one hair styling material as described above in an appropriate medium and on the other hand a propellant, and a dispenser for dispensing said aerosol composition.
The present invention additionally provides a method of treating keratinous fibers, especially hair, in which the composition according to the invention as defined above is applied to the hair before, during, or after the shaping of the hairstyle.
The compositions according to the invention can be rinsed off or not rinsed off the hair.
The present invention additionally provides the use of a composition as defined above in, or for the preparation of, a cosmetic reshapable hair styling formulation.
The composition according to the invention can be provided in any form known from the prior art, which is appropriate for their application to the hair, including in the form of a vaporizable composition, a mousse, a gel, or a lotion.
The determination of whether a polyurethane dispersion can provide a reshapable hair styling composition can be determined by an in vivo test. Specifically, a composition is prepared comprising the polyurethane dispersion and a cosmetically acceptable medium. The medium may be chosen, for example, from water, lower alcohols such as ethanol, and mixtures thereof. The composition typically comprises from about 1% to about 12% by weight active material. The compositions may be in any form noted above, including lotions.
Where the composition is in the form of a lotion, for example, the in vivo test proceeds as follows. The hair of the model is washed and then divided into two symmetrical portions, the right and the left sides. The composition is applied to one side of the head of the model, while a reference composition is applied to the other side of the head. The reference composition may, for example, be chosen from water, an existing commercial product, or another composition under study. The hairdresser dries and styles both sides of the head. The two sides of the head are separately evaluated for the styling effect, the cometic properties, and the reshapable effect. For example, once dried, the hair is brushed in different directions to remove the original styling. The hair is then brushed to restore the original styling. The process of removing the styling, restoring the styling, and evaluating the success of restoring the styling is repeated at least one more time to determine whether the composition is a reshapable hair styling composition. A reshapable hair styling composition permits (1) the original hair styling to be restored after brushing and (2) the creation of a new hair styling after brushing, which may also be restored after brushing. If the composition to be evaluated is in another form, such as a shampoo or conditioner, the in vivo test can be appropriately modified by one skilled in the art.
It is understood that the person skilled in the art would recognize that not all formulations would provide reshapable effect for all hair types during in vivo testing and will know how to formulate and evaluate reshapable hair styling composition in view of the various hair parameters, such as length (short versus long), diameter (thin versus thick), structure (curly versus straight), condition (oily, dry, or normal); and whether the hair is colored, bleached, permed, or straightened. Thus, in vivo testing may require testing on 10-20 different individuals.